1. Field of the Invention
The present invention relates to a touch panel having a robust and well-protected configuration. The present invention further relates to a method for manufacturing the touch panel.
2. Description of the Prior Art
In the market of consumer electronic products, touch panels have been widely applied in various portable electronic products, such as personal digital assistants (PDAs), mobile phones, laptop computers and tablet computers, to serve as an interface tool for data communication. Meanwhile, as the current trend of designing electronic products leans to meet strong demands for lightweight, slimness and minimization, the electronic products thus designed are often too compact to accommodate conventional input devices, such as a keyboard or a computer mouse. More particularly, in a tablet computer with a user friendly design, a touch panel has become a crucial component. In addition to having the capability of displaying a responsive multi-level menu, a touch panel is adapted to present many user-friendly operation modes, including the cursor function traditionally executed by a keyboard or a computer mouse, the handwriting input function, and so on. Especially, the touch panel has the advantage of integrating the input function and the output function in a same interface (screen) and this advantage cannot be achieved by the conventional input devices.
The touch panels available in the market include the so-called resistive-type, capacitive-type and optical-type touch panels. A capacitive touch panel is usually configured to have a multi-layer structure of sensing electrodes, insulative material and conductive traces stacked on a substrate, and this structure is further combined with a control circuit and a liquid crystal display module. The resultant capacitive touch panel is adapted for being installed in an electronic touch control system. When a finger or a stylus pen touches or approaches the capacitive touch screen, the control circuit detects the capacitance change at the touch point to determine the x/y coordinates of the touch point. Therefore, a conventional touch panel is typically composed of a flat transparent plate and a touch sensing structure, with the transparent plate having a touch region for finger and stylus input. Meanwhile, the conventional touch panel normally includes a peripheral region located along the outer periphery of the touch region, on which metal traces are laid out and electrically connected to the control circuit. In some application occasions, the conventional touch panel, if not well-sealed and protected to resist environmental factors, tends to be contaminated by oil, water or solvent stains due to finger contact or is susceptible to other environmental influences. All of these would reduce the reliability of the touch panel.